Wire ropes



y /N VEN TOR $2,225@ Eau/ads 2Mb 22 Y Amm/gm l @Nm/M AM ATTORNEY April2, 1963 R. E. CAMPBELL 3,083,817

WIRE aoPEs /N VE N TOR ima@ Edam@ gwefl 6W' W" 1MM l TTORNE April 2,1963 R. E. CAMPBELL 3,083,817

WIRE RoPEs Original Filed Sept. 10, 1954 5 Sheets-Sheet 3 /A/ VEN TOR`@eze-EZ Ympzell g5 IMIMy-m "cg-MM ATTORNEY April 2, 1963 LL 3,083,817

RRRRRRR ES @ad im@ @QZ BY @um /al/Jd'v l ATTORNEY United States Patent O3,083,817 WlRE RGPES Robert Edward Campbell, Wheatley Hills, Doncaster,England, assigner to British Ropes Limited, Doncaster, EnglandContinuatinn of abandoned application Ser. No. 455,3il0, Sept. 1i?,1954. rEhis application Nov. 2, 1960, Ser. No. 65,76@ Claims priority,application Great Britain Nov. 18, 1953 Claims. (Cl. 265-2) My presentapplication is a continuation of my application Serial No. 455,300,filed September 10, 1954 and now abandoned.

This invention relates to wire ropes and the method ot the invention maybe applied to strands, steel cores and/or finished or partly finishedrope, irrespective of the type of core used or whether the ropes arestranded or locked coil.

The invention is more specically, but not solely, applicable to steelwires which have been isothermally quenched (bringing them into thecondition known as patented) and then cold drawn, It is also applicableto constructions in which, say, liller wires which have not beenisothermally quenched, are incorporated into a strand or core, the otherwires of which have been isothermally quenched. By -the term strand asused throughout the specification and claims is meant a combination ofsteel wires arranged around a central, or king wire, in one or morehelically wound layers, each layer of wires having a specific laylength.

The invention consists of a method of treating steel wire strands, coresor ropes, by imparting thereto a controlled degree of plastic ow withuniform pressure all round.

Anyone versed in the rope-making art would expect that fatigueresistance would be decreased after such treatment, but extensiveexperiments have now shown the contrary to be the case, as anappreciable increase in the fatigue resistance has been tfound to occur.

The invention will be further `described with reference to theaccompanying drawings.

FIGURE 1 is a cross-section of a 6/1 wire strand, prepared in accordancewith the invention, with the strand in the untreated state indicated inphantom.

FlGURE 2 is a similar View of a 9/9/1 strand.

FIGURES 3 and 3a show a plan, and

FIGURES 4 and 4a a side elevation of an apparatus for carrying theinvention into eect.

FIGURE 5 is a cross-section of a 6/1 strand illustrating a correctdrafting A, with two phases of insufficient drafting B and C FIGURE 6 isa cross-section of a 12/6/1 strand prepared in accordance with theinvention.

FIGURE 7 is a cross-section of a 12/6/1 strand with filler wires,prepared in accordance with the invention.

FIGURES 8, 9 and l() show diagrammatically, alternative apparatuslayouts for carrying out the invention.

The basis of the preferred method of operation is the application of thecombined resultant reactive force arising `from plastic iiow undercompression, coupled with predetermined elongation of the strand, whilstpassing through a die of tungsten carbide, hardened steel, ceramic orany other material capable of acting as a drawing medium.

Back tension is applied to the longitudinal axis of the strand as itpasses to the die, of sufficient magnitude to initiate plastic flowprior to the strand entering the die,

whilst not exceeding the limit of proportionality of the i strand (thatis, the point on a stress-strain curve at which the strain ceases to beproportional to the stress).

After treatment as described, it is found in a strand of 3,083,817Patented Apr. 2, 1963 ICC round wires that the originally round wiresmaking up the Strand have individually been reformed to a geometricpattern which, in the case of a layer of six round wires over the king,is as shown in FIGURE l.

When there is more than one layer of wires laid over the king Wire, eachouter Wire cross-section is a pentagon, as illustrated in FIGURE 2. Thatis, the king wire becomes faceted according to the number of wires laidover it, the point of Contact of the next layer of overlying wiresforming the base of a pentagon which abuts a corresponding facet on thepolygonal king wire, the next layer being of reversed pentagons and soon.

In one method of operation the steel wires, which may be round wires inthe plain state, galvanized or treated with any other form ofanti-corrosive or anti-frictional agent, are laid up into the desiredconstruction in a stranding machine, the strand so `formed being coiledon to a reel, preferably of steel or light alloy.

MACHINE SET-UP `In the arrangement of FIGURES 3, 3a, 4 and 4a, the reel1 of the strand is inserted into the cradle 2 and the end taken throughthe fairlead 3. From thence it is led three times around the capstanwheel 4, forward again through the cooling unit S, then into the die 6and finally on to the second capstan or surge wheel 7, where it isallowed to lap round until the surge pad is full, thus attaining maximumtraction. From there it passes through a second fairlead 8 on to thetake-up drum 9 and over traversing gear 9a.

Prior to passing into the die, the strand and the face oi the die aresupplied with a copious stream of lubricant by means of a centrifugalpump 10; the lubricant then gravitates back to the return tank 11. Thedie 6 is watercooled, and it is advantageous to ft a snorter on thestrand as it emerges from lthe Idie as a high degree of follow-throughof the lubricant takes place.

The die-holder 12 of the die `6 is tted on a swivel in the horizontalplane, and can be moved by quadrant and worm 13 by handle 13a so thatwhen required, kill can be imparted to the strand.

IIn operation, having threaded up, the electric power drive 14 :overgear box 14a to the surge wheel 7 is started, and tension applied bymeans of the friction brake 15 with handle 15a on the capstan 4 until apredetermined reading is procured on the :ammeter of the power drive 14,and the |arnmeter reading is kept steady by increasing or decneasing theback tension as required. This virtually ensures reactive drawing of thestrand and greatly increases the life of the die as Well yas initiatingplastic flow as the strand runs into the die.

Additional control may be obtained by employing any hydraulicallyoperated recorder on the friction brake 15, also by la similar type ofrecorder behind the die, which can be used to record the `actual backtension in the strand.

If necessary, the requisite deviation of the die from its longitudinalaxis is then set by the worm and quadrant 13, and the machine is openedup to full speed.

Rotation of the cradle 2 can -be effected las desired by means of thepower drive 16 over the gears 17, and the reel 1 is braked by means ofthe lfriction brake 18 with brake band tension 19.

Whilst the die iand die-holder have been shown fixed during theoperation, these two can be built up so that they -are capable ofrotation around fthe longitudinal axis of the strand by an independentdrive, whilst the strand is being drawn through the die.

The main advantage is that a considerable reduction in the horse powerrequired to draw the strand through the die is effected, particularlywhen the die is revolved `at high speeds, in the order of 4,000 to5,00() rpm. Further advantages are, that the life `of the die isprolonged due to the prevention of uneven wear of the effective drawingportion of the die, that ovality of the strand reduced, coupled withbetter follow-through of the lubricant used whilst drawing.

In place of a mechanically operated die, as described,

it is also possible to carry out the operation in a like manner, bythreading the strand through :the center of a four jawed chuck fittedinto roller bearings. y Between :the bearing :and the rear Iof fthechuck, a toothed driving wheel is built in as an integral part of thechuck, .and geared lto a high speed motor, which imparts the requiredrotation to the chuck in either a clockwise or anti-clockwise direction.

'I'he jaws of the chuck are fitted with parallel or convexed surfacedhardened steel or tungsten carbide rollers.

In operation the jaws of the chuck are closed until the diameter betweenthe roller faces the final diameter at which it is required to producethe strand. They are then locked in this position, and the tapered endof the strand fed through as in the case of a die, to the pullinginstrap, and the chuck rotated at the requisite speed, with the lay of thestrand.

The strand is then pulled forward through the rotating chuck, thus.attaining the requisite degree of drafting and internal geometricpattern in the individual wires.

IOINTING AND HAULING-IN THE STRAND Any method which will produce `agraduated taper at the end of the strand to allow its insertion into thedie can be employed such las twisting the end of the strand While it ishot and then grinding Vto the requisite degree of taper; oralternatively by svn-aging.

The free end of the strand is inserted into the die until a sufficientlength is available to .allow a pulling-in strap,

but also to 4'give satisfactory performance when in service .as Ia ropelubricant.

Whilst this lubricant is considered to give the most satisfactoryresults, owing to the factors detailed above, any material which :actsas a lubricant and permits off drawing, can be used to operate thisprocess.

COOLING SETTING UP OF O'PTIMUM CONDITIONS In order to obtain the maximumefficiency from a drawn strand, the optimum controlling factors must beaccurately established for each construction of strand to be treated andthese factors are:

(l) The Percentage Redaction in Area of the Entire Strand (Drafting)Which Gives Correct Geometric Compactng of the Strand If the reductionis correct, in the case of -a strand with a single layer of wires over aking wire the outer wires deform to a wedge shaped cross-section, thebase of which fits to the facet on the king wire, the crown beingradiused to form a composite part of the circumference of the strand.

or rope, to be attached to it by means of grips, the pullingin strapbeing connected to the haul-off capstan.

The machine can then be operated until a sufficient length of strand hasbeen drawn through the die to permit of lapping around the haul-offcapstan, and on to the take-up reel.

vAs soon as the initial lengthkof strand has been run through themachine, as described above, and secured to .the take-up reel, the diebox is set to the requisite angle with the quadrant control, and thenecessary back tension applied -via the brake band on the first capstannear the pay-off reel. All the necessary factors are now under control,according to the pre-set conditions, and uninterrupted drawing canproceed.

DIESv The dies are conveniently :orthodox wire drawing dies ofconventional pattern, made of tungsten carbide, and runs vofwell over .aton with such dies, employing a 27% drafting on 10G/110 ton tensilematerial in the outer wires l ave `been successfully accomplished,without any deterioration of the die surface, and with the speciallubricant used, fthe die should remain on size.

Although ydies made of tungsten carbide have been used, `any materialcapable of withstanding the bursting strains, coupled with the requisitehardness to take a high polish to draw, is suitable.

LUBRICANTS The lubrication is basically a highly refined mineral oilintowhich additives have been incorporated to give:

(l) Good drawing properties. (2) Good lubricating properties. (3) Highstability under compression.

(4) Maximum water repellency. (5 Resistance to dissociation at elevatedtemperatures.

The lubricant is one which is intended not only to enable the drawing tobe done with maximum efficiency,

In section A FIGURE 5, we have the correctly compacted geometric shapeattained by the optimum drafting. Failure to apply the requisite optimumdrafting will result in cooking of the outer wires and tubing of theouter cover, the varying degrees depending upon the percentage drafting,with the formation of a bird-cage when drawn.

To clarify the importance of selecting the optimum draft, the followingexamples are quoted to demonstrate the resultant effect.

In section B FIGURE 5, we have a `case where too light a drafting hasbeen employed and, under such circumstances, the outer wire has beenunable to compress the king Wire, and consequently, is expanding to ranellipse, with resultant tubing of the cover, or lifting of the outerwires away from the king Wire; the wire deforma- -tion then becomesinconsistent and finally a wire lifts right out and the whole strandbird-cages and malforrns.

In section C FIGURE 5, an intermediate phase is demonstrated; this takesplace when a drafting lying between the correct one and one thatproduces the result described in the previous paragraph, is applied. Insuch an instance the wire is plastic-ally deformed to the requisitegeometric shape, but is unstable upon its axis and it tilts tangentiallyto the circumference of the strand, producing two convergent planes onthe crown or contact position ofthe outer wires.

The line D-E illustrates the .tangential flat which is produced on thesurface of the individual Wires when an insufficient degree `of draftinghas been employed. Consequently, in the wire marked C, instead of havinga uniform radius on the external surface, or drawn position, atangential flat is formed. This causes the deformed wire to tilt uponits 'axis and give the appearance of a worn strand, instead of allowingthe wire to correctly defo-rm to its full geometric pattern and securecomplete locking in the strand.

In FIGURE 5, reference 3x refers to the continuous black line at thebase of the correctly formed wire at A and shows how, as a result of theking wire being faceted, the overlying wires have a correspondingly firmbase upon which to rest. To illustrate the importance of correctdrafting still further, it will be seen that the oval section B cannotform a flat surface, but a spessi? slightly concave depression, whichallows of rolling or rocking of the wire about its axis on the kingwire, instead of its being firmly seated.

FIGURE 6 shows the 12/6/ 1 construction cross-section without llerWires, after drawing, `and shows that the wires of the intermediatelayer `between the king wire and the outer wires become pentagonal.

FlGURl-E 7 shows the eifect of iiller wires (ie. the small diamondshaped wires) which add an extra side to the pentagonal shaped Wiresover the king wire, also an extra side to the outer wedge shaped wires.

Any combination of iiller wires interposed between the round wiresproduces the diamond shape in the filler wire with the correspondingextra side on the pentagonal shaped wires.

(2) Adjustment of Drafting to Maintain Geometric Pattern, and ProduceSelected Physical Characteristics Having determined the requisitedrafting to produce the required geometric shape, it is then necessaryto determine the drafting which not only maintains the correct geometricpattern but gives maximum physical characteristics, thus producing anincreased service life in the strand and ultimately the completed rope.

in order to obtain positive assurance upon this point, it is advisableto vary the drafting on either side of the one selected to give therequired geometric pattern, so that a series of sample lengthsbracketing the required geometric configuration are obtained; theresultant sarnples are tested to destruction for tensile and fatigueresistance, whilst modulus, lay, loss in weight and increase in lengthper unit length, are also determined and plotted graphically.

By careful interpretation of the graphical trends on each plot, it ispossible to adjust the drafting to give a maximum reading on all thephysical characteristics at the selected draft.

it should be noted that when the drafting is at the optimum, all thegraphical plots are in ratio to one an other and follow the same trends.

The prior drafting, namely that to which the rod has been subjectedwhilst being drawn into wire, can have a material eiiect upon theoptimum strand drafting, 'therefore, typical graphical plots cannot beconstructed to cover all wire supplies and consequently the proceduredetailed above must be employed.

(3) Design of Strand in Relation to Tensile 0f Wire The physicalcharacteristics of a strand, and the iinished rope, can be extended ifthe strand is designed with the various layers of wires not of onetensile, but each layer of a different range so that the amount ofsecondary drawing in the respective layers (ie, the drawing of the wiresof the strand due to drawing of the strand as opposed to the primary orinitial drawing of the Wires themselves in their manufacture) may bebrought to the same degree in the iinished strand, or intentionallymaintained at selected amplitudes; this has been found to have animportant bearing upon increased resistance to fatigue.

(4) The Optimum Drafting Required for any Given Construction of StrandThis is critical, the reason for this being due to the fact that as thedrafting applied to any given strand is progressively increased, thefollowing stages tak-e place:

(a) The existing air space between the individual wires in the strandbegins to diminish;

(b) The point contact of the individual round Wires begins to increase,due to the resultant reactive force exerted by the compression throughthe die, on the circumference of the strand, and the back tension fromthe reactive capstan;

(c) The air space continues to diminish whilst the wires are rapidlycommencing to flow plastically.

When the drafting is applied in the range of %-40%,

the full geometric pattern is attained, and the air space within thestrand has disappeared. Except for the thin rtilm of oil, the strand hasvirtually become a solid bar proved by the modulus rising rapidly to aclose approximation to the modulus of a solid steel bar.

Normally, ir" 30% drafting is exceeded, the strand lbegins to drawpurely as if it is a solid bar, demonstrated by the fact that thegeometric cross-section of the wires is not changed, but that the laylength increases. In certain types of strand particularly those in whichfiller wires are included, this elect is delayed until as much as .40%drafting is given.

The optimum drafting would appear, from experiments, to be around271/2%. This iigure varies with thev different constructions, and evenmore so where the respective covers in a strand are built up with wiresof different tensiles because the rates of plastic deformation are boundto vary.

(5) T he Optimum Back Tensioning Force According to the construction ofthe strand, and the tensile of the Wires employed, the back tensioningforce will range from, say, 12% to 35% of the breaking load of thestrand.

This would apply not only to the 9/9/1 strand, but to any construction,and initially would be ascertained by taking the breaking load of thestrand before drawing, and then applying the requisite percentage ofthat breaking load, but always keeping it below the limit ofproportionality. (See definition above.)

The back tension can be measured by means of any lydraulically operatedrecorder incorporated behind the TYPES OF STRANDS The process andequipment as described has dealt with the treatment of strand Whereround wires have been concentrically disposed around a king wire. Bysubstituting triangular or oval-sectioned dies for a round one, and thebuilding up of suitably constructed strand to allow ofY geometricreorientation, flattened, triangular or oval strands of any desireddegree can also be produced with the same equipment and basicprinciples.

It should also be noted that the method is applicable to armoured orindependent wire rope cores, also to strands whose cores are composed ofplastic, either in the -form of a solid rod or containing a conductor,when improved fatigue resistance results.

Selection of the requisite tension and twist to the strand whilstdrawing enables the internal lubrication to be introduced into thestrand and then sealed in by the plastic iiow on the crown of the outerWires, of which the strand is composed.

Selection of an optimum overall reduction on the initial strand diameterin relation to the particular contruction used, results in an increasein the tensile strength of the strand, without loss of fatigue strength.

ROPES The strands prepared in the manner detailed above are loaded intoa rope making machine and closed into the completed rope, over anyselected type of core.

The completed rope may then, if desired, be passed through a die in asimilar manner, thus a controlled degree of plastic flow is imparted tothe crown of the strands with uniform pressure all around thecircumference of the rope. By this means, initial bedding of the strandsto the core occurs, so that when the rope is put to work, no settlingperiod is necessary within its designed working load, and it is lessliable to elongate within its working range, especially when preformed.

Alternative layouts for treating strand in accordance with the inventionare shown in FIGURES 8, 9 and 10 of the accompanying drawings.

a In FIGURE 8 the strand on a pay-off swift 20 is drawn in exactly thesame way as steel wire, except that the die 21 is not only water cooledbut immersed inthe lubrieating medium in oil bath 22 and the strandbefore ventering the die passes around pulley 23 which is fitted with abraking device (not` shown) to `give the necessary back tension. Thestrand after drawing is taken up on the drawing block 24. n

. In FIGURFl` 9 the strand pays off the swift 2t), around pulley 23which is again fitted with a braking device, but inthisV instance thetension applied is of sufficient magnitude to keep the strand taut. -Inthis method no back tension, in the true sense, is applied from thispulley. i

The st-rand is then lapped three or four times around the drawing block'25, led' through a lubricating bath 22 and die 21 on tothe seconddrawing block 2 6. l

`To Aopera-te the process, the two blocks and 26 are driven by variablespeed motors and to attain the necessary back tension the drawing blockat 25 is runat a specified number of revolutions per minute slower thanblock 26. This allows the initiation of lplastic flow under controlledconditions, 'prior to the strand entering the ldie 21.

In FIGURE 1'0, the strand comes ot the pay-off swift 20 over the capstanwheel 27 which is fitted with a braking device to apply back tension andis situated vertically over the haul-ofi capst-an at 28. 'Ihe die 21 andlubricating Ybath 22 are situated between the two capstans 27 and 28.From thence the strand progresses forward on to the haul- -olf reel 29.

It will be lappreciated that this method is virtually the same as thatin FIGURES 3, 3a and 4, 4a but the strand is actually drawn, and backtension applied, in the Vertical plane as against the horizontal. Thiswould conserve floor space.

As an alternative to the use of ardrawing die in the above describedembodiments of my invention a swaging machine may be substitutedtherefor with all other factors remaining the same.

In this particular application, whilst the final form is th'e same asthat obtained by pulling through a die, it is produced by the combinedresultant reactive force arising from predetermined elongation of thestrand, whilst subjected to vrapid cyclic compression around thecircumferenceof thestrand by mechanical means, using segmental dies,i.e. swaging. 4 g, l

The process of lthe invention results in:

(l) 'Reduction to a minimum of the air space within the strand. n 1 I p(2) The production, around the longitudinal axis of the strand, of anatural correlated geometric shape in all the wires of which the strandis composed, including the king.

(3) Reduction of the interstices'between the wires com- 'H posing thestrand,particularly the outer wires.

.( 4) An increase of the internal contact area ofthe wires 'inf thestrand, and improved compressional resistance when 'spun into a rope.

The above factors, when applied to a steel strand, result in:

(l) A considerable increase in the breaking load of a ropesize forsize-due to 'the increased volume of steel, `which is proportionate tothe diminution of air space within the rope, the remainingsmallpercentage of non-metallic material being the internal lubricant, forcedinto the Astrand when drawing.

'to their geometric shape, `which not only occurs in each individualcover, but the underlying and overlying covers too.

(b)` A plastically flowed surface film on the working or contact area ofeach strand which gives added fatigue resistance.

(c) The formation` of geometric helical wedges (see cross-sectionaldiagram FIGURE 6) which give the strand, and consequently the rope, highresistance to compression CIL and malformation, thus ensuring thatdifferential working of the wires is minimized, with consequentelimination of premature fatigue in individual wires. Contrary to whatmight be anticipated, it is especially noticeable when strands, or 'thetinal'rope are subjected to fatigue tes't, that no premature failure ofindividual wires is experienced until the full expectation of fatiguelife is obtained; at this stage progressive failure of the individualwires then ensues in the normal way, the outer wires failing bysquare-ended fatigue and 'the inner Wires by pure tensile, thus provingthat when this condition does ultimately occur, it takes placeexternally not internally, giving adequate warning of impendinginability to sustain a load. This is due to the increased bearingsurface and inability of the wires to roll and the strand malform.

(d) Even bedding of the strand to the core, which produces 'a tighterspun, less lively rope with improved iiexibility, Whilst the strandsthemselves, if drawn to an optimum, exhibit what are virtuallymicrointerstices of uniform consistency. That is, they are completelyfree from gappiness, and are of uniform diameter, whilst the smoothsurface of the strand allows controlled movement without the developmentof frictional forces and possible damage to the strand itself, or thecore.

Both the strands, and consequently the finished rope, have a smoothsurface, and as a result are easy to handle, the above factors againadding to the fatigue resistance, due to the fact that the surface layerof the strands has been plastically flowed, and the notch sensitivity ofthe component wires reduced.

(3) Increased anti-corrosion properties, due to the drawing lubricantused, which not only has a high degree of efficiency as such, but 'hasbeen designed to act as a rope lubricant of high order, to permeate thewhole of the strand, thereby securing maximum water repellency.

I claim:

1. A process of transforming `an `initial rope strand having a givendiameter and cross-sectional area of metal and comprised of at least onelayer of circular Wires helically laid around a circular king wire andhaving spaces therebetween into a finished rope strand of substantiallysolid metal cross-section of smaller diameter and smallercross-sectional area than the initial rope strand and comprised of aking wire of polygonal cross-section having a number of iiat facescorresponding to the number of wires in said one layer of wires, thewires in said one layer of said finished rope 'strand being of the sainepolygonal cross-section, 'each having one flat face coextensive with andengaging flush against a respective fiat face of the king wire of the`finished rope strand, and having side flat Vfaces extending radially ofthe axis of the king wire of the finished rope strand and coextensivewith and engaging flush against the side flat faces of the wiresadjacent there- .ceeding the limit of proportionality of said initialrope strand but sufficient to bring the same to a state of incipientplastic iiow, before the compressive load is applied whereby toL reducethek diameter and the cross-sectional area of all `of the wires of saidinitial rope strand, and to shape all the wires'to mutually engagingpolygonal cross-section as aforesaid and thereby/provide said finishedrope'strand of substantially solid metal cross-section.

` 2. A process of transforming initial rope strand as set forth in'claim 1,'wherein the tensile load imposed on said length of initialrope strand is at a `constant value which lies between about 12% toabout 35% of the breaking load of the initial rope strand.

3. A process of transforming initial rope strand as set forth in claim1, wherein the compressive load applied to said length of said initialrope strand is of an amount to reduce the cross-sectional area thereofby a xed value in a range of from about 20% to about 40% of its originalcross-sectional area.

4. A process of transforming initial rope strand having a given diameterand cross-sectional area of metal and comprised of at least one layer ofcircular wires helically laid around a circular king wire and havingspaces therebetween into a iinished rope strand of substantially solidmetal cross-section of smaller diameter and smaller crosssectional areathan the initial rope strand and comprised of a king wire of polygonalcross-section having a number of ilat faces corresponding to the numberof wires in said one layer of Wires, the wires in said one layer of saidiinished rope strand being of the same polygonal crosssection, eachhaving one flat face coextensive with and engaging flush against arespective flat face of the king wire of the linished rope strand, andhaving side ilat faces extending radially of the axis of the king wireof the finished rope strand and coextensive with and engaging iiushagainst the side at faces of the wires adjacent thereto in said onelayer of said finished rope strand, comprising the steps of moving theinitial rope strand in one direc` tion through a path in one part ofwhich a length of said initial rope strand extends along its lengthwiseaxis,

simultaneously applying a radially inwardly directed com- 30 pressiveload at one portion only of said length of said initial rope strand inan amount to reduce its diameter to a xed value within the range of fromabout 20% to 40% of its original diameter while imposing an accuratelycontrolled constant tensile non-compressive load axially on the part ofsaid length of said initial rope strand approaching said one position offrom about 12% to about 35% of the breaking load of the initial ropestrand so as not to exceed the limit of proportionality of said initialrope strand but suicient to bring the same to a state of incipientplastic flow, said compressive and tensile loads together reducing thecross-sectional area of and shaping all the wires of the initial ropestrand to mutually engaging polygonal cross-section as aforesaid andthereby provide said nished rope strand of substantially solid metalcrosssection.

5. A process of transforming initial rope strand as set forth in claim 1wherein the compressive load applied to said length of initial ropestrand is of an amount to reduce the cross-sectional area thereof to aiixed value of about 271/2 of its original cross-sectional area.

References Cited in the le of this patent UNITED STATES PATENTS1,943,087 Potter et al. Jau. 9, 1934 2,050,298 Everett Aug. 11, 19362,062,059 Hodson Nov. 24, 1936 2,095,461 Whyte Oct, 12, 1937 2,098,922McKnight Nov. 9, 1937 2,156,652 Harris May 2, 1939 2,445,365 ReardonJuly 20, 1948 FOREIGN PATENTS 7,535 Great Britain 1905 14,121 GreatBritain 1891 143,096 Australia Aug. 28, 1951 438,275 Germany Dec. 15,1926

1. A PROCESS OF TRANSFORMING AN INITIAL ROPE STRAND HAVING A GIVENDIAMETER AND CROSS-SECTIONAL AREA OF METAL AND COMPRISED OF AT LEAST ONELAYER OF CIRCULAR WIRES HELICALLY LAID AROUND A CIRCULAR KING WIRE ANDHAVING SPACES THEREBETWEEN INTO A FINISHED ROPE STRAND OF SUBSTANTIALLYSOLID METAL CROSS-SECTION OF SMALLER DIAMETER AND SMALLERCROSS-SECTIONAL AREA THAN THE INITIAL ROPE STRAND AND COMPRISED OF AKING WIRE OF POLYGONAL CROSS-SECTION HAVING A NUMBER OF FLAT FACESCORRESPONDING TO THE NUMBER OF WIRES IN SAID ONE LAYER OF WIRES, THEWIRES IN SAID ONE LAYER OF SAID FINISHED ROPE STRAND BEING OF THE SAMEPOLYGONAL CROSS-SECTION, EACH HAVING ONE FLAT FACE COEXTENSIVE WITH ANDENGAGING FLUSH AGAINST A RESPECTIVE FLAT FACE OF THE KING WIRE OF THEFINISHED ROPE STRAND, AND HAVING SIDE FLAT FACES EXTENDING RADIALLY OFTHE AXIS OF THE KING WIRE OF THE FINISHED ROPE STRAND AND COEXTENSIVEWITH AND ENGAGING FLUSH AGAINST THE SIDE FLAT FACES OF THE WIRESADJACENT THERETO IN SAID ONE LAYER OF SAID FINISHED ROPE STRAND,COMPRISING THE STEPS OF MOVING THE INITIAL ROPE STRAND IN ONE DIRECTIONTHROUGH A PATH IN ONE PART OF WHICH A LENGTH OF SAID INITIAL ROPE STRANDEXTENDS ALONG ITS LENGTHWISE AXIS, SIMULTANEOUSLY APPLYING A RADIALLYINWARDLY DIRECTED COMPRESSIVE LOAD AT ONE PORTION ONLY OF SAID LENGTH OFSAID INITIAL ROPE STRAND WHILE IMPOSING AN ACCURATELY CONTROLLEDPREDETERMINED CONSTANT TENSILE NON-COMPRESSIVE LOAD AXIALLY ON THE PARTOF SAID LENGTH OF SAID INITIAL ROPE STRAND APPROACHING SAID ONE PORTION,THE VALUE OF THE TENSILE LOAD NOT EXCEEDING THE LIMIT OF PROPORTIONALITYOF SAID INITIAL ROPE STRAND BUT SUFFICIENT TO BRING THE SAME TO A STATEOF INCIPIENT PLASTIC FLOW, BEFORE THE COMPRESSIVE LOAD IS APPLIEDWHEREBY TO REDUCE THE DIAMETER AND THE CROSS-SECTIONAL AREA OF ALL OFTHE WIRES OF SAID INITIAL ROPE STRAND, AND TO SHAPE ALL THE WIRES TOMUTUALLY ENGAGING POLYGONAL CROSS-SECTION AS AFORESAID AND THEREBYPROVIDE SAID FINISHED ROPE STRAND OF SUBSTANTIALLY SOLID METALCROSS-SECTION.